The invention relates to an optical receiver circuit of the type as specified in the preamble of patent claim 1 and an optical receiver as specified in the preamble of patent claim 14.
Optical communication systems are nowadays widely used in home networks and industrial applications, for example, the MOST (Media Oriented Systems Transport) technology used in the automotive industry for high-speed multimedia networks is based on plastic over fiber (POF) technology.
In said optical communication systems, as for example described in US 2013/0330082 A1, a light emitting device, the optical transmitter, outputs an optical signal that is fed into an optical fiber link, e.g. a plastic fiber, which guides the optical signal to a light receiving device, the optical receiver, which comprises a photo detector for receiving the optical signal.
Such optical communication systems inter alia have several advantages compared with the conventional non-optical communication systems over copper: e.g. lower attenuation, immunity to electromagnetic interference irradiation and higher data rate transmission. In recent years optical communication systems are therefore more and more also used for in-vehicle data communication.
Current optical communication systems however are inter alia suffering from the challenge that, the optical communication system, in particular the performance of the optical receiver, does not adequately deal with variations in received optical powers that can span several orders of magnitude, resulting in undesired noisy and non-linear behavior of the electric output signal of the optical receiver.
Furthermore, the performance of the optical receiver can degrade due to, for example, undesired fluctuations in voltage, temperature and/or due to local process variations (also called process variations for brevity), i.e. due to naturally occurring variations in the attributes of electronic components such as transistors when electronic integrated circuits are manufactured.